1. Field of the Invention
The invention relates to an improved endotracheal tube or an adapter for a standard endotracheal tube to allow the performance of various medical procedures while maintaining continuity of respiration.
2. Information Disclosure
Endotracheal intubation is the insertion of a hollow, pliable tube into the trachea. In human patients the tube is usually passed through the mouth, or less commonly through the nose, into the trachea extending approximately to the carina, anterior to a position between the second and fourth thoracic vertebrae. After the endotracheal tube is placed in the correct anatomical position, the end extending from the mouth (or nose) is attached to an oxygen source and mechanical ventilation is performed. The tube is commonly 14 to 30 cm long, 2.5 to 9.5 mm inside diameter and is furnished with a tapered adapter at the top for attaching the mechanical ventilator. A conventional endotracheal tube is shown in FIG. 1. Endotracheal intubation is indicated (1) when there is inadequate spontaneous ventilation or when there is evidence of insufficient oxygenation and the inadequacy is not corrected by supplemental oxygen from a mask or nasal cannula; (2) when there is a need to control and remove pulmonary secretions; (3) when drugs are to be administered directly into the lung and (4) when there is a need to provide airway protection in an obtunded patient or a patient with a depressed gag reflex. In an emergency setting, endotracheal intubation is often performed as a precaution when there is a possibility of any of the foregoing conditions.
The insertion and manipulation of a conventional endotracheal tube, particularly in an emergency, is fraught with potential hazard to the care provider because of the risk of contacting infected body fluids. In the past several years there has been world wide attention to the problem of contamination with regard to several problematic contagious diseases. Three major diseases posing a threat to patients and health care providers in the context of endotracheal intubation are: (1) AIDS (Acquired Immunodeficiency Syndrome), the pulmonary symptom presentation of which includes pneumonia, M-tuberculosis, and bronchiolitis; (2) drug resistant pulmonary tuberculosis; and (3) meningitis. All three can be spread by contact with pulmonary secretions of infected patients.
These and other respiratory infective diseases have contributed to the awareness that care providers must treat the blood and body fluids of all patients as potentially infectious and this awareness has given rise to the establishment of a set of "Universal Precautions."
Conventional endotracheal tubes pose a significant risk of contamination whenever the respiratory circuit is broken, and the circuit must be broken to administer drugs, to irrigate or to suction.
Among the more common conditions that require endotracheal intubation is cardiopulmonary arrest, which is treated commonly in hospital emergency departments and in pre-hospital settings. Typically, in patients experiencing cardiopulmonary arrest, mechanical ventilation with oxygen is in itself not sufficient to resuscitate successfully. Therefore, in addition to artificial ventilation, certain drugs may be necessary to help "restart" the heart. These drugs may be introduced into the patient's bloodstream via an intravenous cannula placed in a systemic vein, such as an arm vein or large chest vein (in contrast to a pulmonary vessel). However, in recent years, it has been found that certain life-saving drugs, such as epinephrine, atropine, and lidocaine, also may be administered through the pulmonary (lung) vasculature. Patients receiving these drugs for cardiopulmonary arrest, or receiving other drugs such as naloxone and valium for other indications, via the pulmonary route respond in a similar fashion to those patients receiving drugs via systemic (arm or chest) administration. As a result, it is now the accepted standard practice to use the endotracheal route for life-saying drug administration if for some reason systemic venous access is not available.
Since cannulating a systemic vein is time-consuming or even impossible in many situations, and since time is of the essence in administering life-saving drugs, the endotracheal route is often used in an emergency setting. Currently, the accepted technique for endotracheally administering drugs involves the injection of the selected drug into the proximal end of the tube and then "blowing" the drug down the tube into the lungs. Injection of the drug into the proximal end of the endotracheal tube using conventional tubes requires hyperventilating the patient, disconnecting the mechanical ventilator from the top of the endotracheal tube, instilling the medication and reattaching the ventilator. During the period of instillation, when the top of the tube is open, the medication, along with a certain amount of sputum, is often expelled back out as a result of cardiac compression efforts or as the result of an involuntary cough reflex due to irritation of the lungs. When there are thick pulmonary secretions, saline is also administered and the lungs are suctioned. This operation, as well, requires hyperventilating and breaking the circuit, once again exposing the care provider to risk of contact with infected fluids. The problem is exacerbated in this case because the significant accumulation of secretions and saline triggers a cough reflex which shoots the secretions out of the open tube. Since the intervention must be repeated every five to ten minutes in many cases, there is an enormous risk of exposure to infected fluids on the part of the care provider and a significant hazard to the patient as well because of the cycles of hyperventilation and absence of ventilation.
There is thus a need for an improved endotracheal tube that would allow uninterrupted mechanical ventilation and that would protect the care provider from exposure to contaminated fluids.
Another problem that occasionally arises during the instillation of drugs into the open end of the endotracheal tube is that of the needle dislodging from the syringe that is being used to administer drugs or saline into the tube. For administration many drugs and saline are drawn up into a medical syringe via an attached hypodermic needle. The needle is attached to the syringe by a tapered friction connector. When the plunger on the syringe is pushed to expel the fluid, pressure builds up in the area of the connector, and if there is no back pressure on the fitting from the shaft of the needle, the needle has been known to dislodge from the syringe and travel down the endotracheal tube, causing serious complications.
There is thus a further need for an improved means of allowing the introduction of medication into the endotracheal tube while preventing the introduction of other foreign matter and objects.